Pumping devices for fluid containers are in general provided with an actuator and a head part connected to the fluid container. Between the actuator and the head part a coil spring is provided in order to repel the actuator from the head part. As the actuator is pushed downwards, an outlet valve in the actuator is opened and fluid is dispensed through an orifice or a spray nozzle. When the actuator is released it will return to its starting position and simultaneously an inlet valve at the head part will be opened and fluid in the container will be sucked into the pump chamber between the actuator and the head part.
These known pumping devices have many different parts with a complicated structure and therefore they are tedious to manufacture. Further the coil spring is normally made of spring steel which has to be protected from the liquid in the container. Another drawback is that the different parts of the pump devices have to be assembled manually.
U.S. Pat. No. 6,227,414 B1 describes for instance a dispensing device for liquid with a support in an opening of a receptacle which encloses the product to be dispensed. The support has a central tubular conduit, a pushbutton axially slidably mounted on the support between a rest position and an active position and a product outlet conduit. An intermediate piece of a resiliently deformable material is provided between the support and the pushbutton. The intermediate piece and the pushbutton define a measured quantity chamber for the product. The intermediate piece has an opening for communication between the tubular conduit of the support and the measured quantity chamber, and sealingly bears against at least one opening for passage between the measured quantity chamber and the outlet conduit of the pushbutton.
A drawback of this known dispensing device is that the outlet conduit is ending in the upper cap of the pushbutton and therefore not very practicable. In addition since there are two parallel walls in the intermediate piece which have to be stretched if the pushbutton is actuated the resilient resistance is quite high. Another drawback is that the dispensing device might drip after dispensing the product.
In DE 10 2008 029 004 A1 a dispenser is described for dispensing fluid or pasty products with a supply chamber, a head piece, a pump chamber, an inlet valve and an outlet valve, wherein the pump chamber is made as an integral body from a resilient plastic material. The pump chamber body comprises a bottom connection part which is formed as a ring collar. The outlet valve exists of a separate flat piece which is cooperating with the pump chamber body. If the head piece is actuated the pump chamber body is pressed down so that it is bulged. Therefore the volume of the pump chamber is only marginally reduced by the pump chamber body and the pump action is less efficient as with a piston cylinder embodiment.